• PNF and Movement
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• v.14 no.1
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• pp.23-32
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• 2016

Purpose: The purpose of this study was to determine the effects of a coordinative locomotor training program on the functional movement screen (FMS) scores of badminton players. Methods: The participants consisted of 31 badminton players who were randomly assigned to either an experimental group (n=15) or a control group (n=16), and engaged in exercise five times per week for six weeks. The experimental group engaged in coordinative locomotor training and the control group engaged in general exercise. An FMS kit (USA) was used to measure the following: FMS score, deep squat, hurdle step, in-line lunge, shoulder mobility, active straight leg raise, trunk stability push up, and rotary stability. Results: The FMS score, deep squat, hurdle step, in-line lunge, active straight leg raise, and trunk stability push up showed significant improvement in the experimental group (p<0.05). Conclusion: The coordinative locomotor training program was able to produce confirmation that functional movement screen scores change in the case of effective exercise interventions in badminton players.

• Journal of Korean Physical Therapy Science
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• v.29 no.1
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• pp.64-72
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• 2022

Background: The purpose of this study is to investigate the effect of wall squat exercise according to the difference in the support surface on the thickness change of external oblique, internal oblique and transverse abdominalis of the trunk muscles and the change in distance of center of pressure when the eyes are opened and closed. Design: Randomized controlled trial. Methods: The subjects were 26 healthy adults, 18 males and 8 females. The composition of each group using the single-blind method was 13 people in the unstable side wall squat exercise group and 13 people in the stable side wall squat exercise group. Experimental measurements were divided into before, 3 weeks, and 6 weeks after the experiment, and changes in muscle thickness and balance were confirmed. Muscle thickness was measured using ultrasinic, and static balance change was measured using Bio-rescue. Results: There were significant differences in the thickness changes of external oblique, internal oblique and transverse abdominalis according to the wall squat exercise method by period and in the interaction between the period and the group (p<0.05). As a result of the post-hoc analysis, there was a significant difference in the change between the two groups in external oblique muscle after 6 weeks. And there was a significant difference in the distance of the pressure center between eyes open and closed eyes (p<0.05). Conclusion: In terms of instability, wall squat exercise was positive for changes in trunk muscle thickness. It suggests the possibility of using it for trunk muscle strengthening training in the future.

• Korean Journal of Applied Biomechanics
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• v.32 no.2
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• pp.49-55
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• 2022

Objective: This study aims to verify the front squat motions using by two different surfaces, thereby elucidating the grounds for effective training environment that can minimize the risk of injury. Method: Total of 10 healthy male crossfit athletes were recruited for this study (age: 32.30 ± 3.05 yrs., height: 173.70 ± 5.12 cm, body mass: 82.40 ± 6.31 kg, 1RM: 160 ± 13.80 kg). All participants are those who know how to do front squats well with more than five years of crossfit athlete experience. All participants have sufficient experience in front squats on two types of surface which are soft surface (SS) and hard surface (HS). In each surface, participant perform 10reps of the front squat with 80% of the pre-measured 1RM. A 3-dimensional motion analysis with 8 infrared cameras and 2 channels of EMG was performed in this study. Paired sample t-test was used for statistical verification between two surfaces. The significant level was set at α=.05. Results: The significantly decreased rectus femoris muscle activation was found in SS compared with that of HS on phase 1 (p<.05). Also, ROM of ankle joint was significantly increased in the SS compare with that of HS on phase 1 (p<.05). The muscle activity ratio of gluteus maximus/rectus femoris showed a significant difference only in SS compared with that of HS on phase 1 (p<.05). Conclusion: In conclusion, Korean crossfit boxes should consider the use of hard surface, which has a relatively less risk of injury than soft surface, in selecting flooring materials. For the Crossfit athletes, they are also considered appropriate to train on a relatively hard surface.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.22 no.1
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• pp.9-15
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• 2016

Background: This study was conducted to investigate the effects of unstable modified wall squat exercises accompanied by abdominal drawing-in on the gait variables of healthy adults. Methods: The total number of subjects was 30, and 15 were randomly placed in the training group (TG) and 15 in the control group (CG). To determine the gait variables of TG and CG, step length difference (SLD) stance phase difference (STPD), swing phase difference (SWPD), single support difference (SSD), and step time difference (STD) were measured using OptoGait, a gait analysis system. Results: When the pre-intervention and post-intervention results of TG and CG were compared, statistically significant differences in SLD, STPD, SWPD, SSD and STD of TG were seen. Conclusion: Unstable modified wall squat exercises accompanied by abdominal drawing-in might help reduce the deviation between left and right gait variables during walking.

• Korean Journal of Applied Biomechanics
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• v.32 no.4
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• pp.134-140
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• 2022

Objective: This study aims to verify effect of 1-RM direct measurement method of back squat on beginners. Method: Total of 8 healthy adults were recruited for this study (age: 29 ± 3.81 yrs., height: 174 ± 3.83 cm., body mass: 74 ± 11.63 kg., 1RM: 96 ± 19.78 kg). All participants performed the back squat with 80%, 90% and 100% of the pre-measured 1RM. A three-dimensional motion analysis was performed with 8 infrared cameras and 3 channels of EMG were used for this study. One-way ANOVA with repeated measure was used for the statistical analysis with the significant level set to α=.05. Results: The ankle joint ROM in the transverse plane was significantly increased as the weight increased during the concentric contraction phase 2 (p < .05). In addition, the erector spinae and the gluteus maximus, which are synergist for the motion, showed a significant difference according to the increased weight (p < .05). Conclusion: Our results revealed that beginners increase potential dynamic knee valgus as weight increased. Therefore, it is thought that field coaches should pay attention to this to minimize and prevent injuries when measuring 1-RM for beginners.

• Journal of Korean Physical Therapy Science
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• v.31 no.3
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• pp.23-30
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• 2024

Background: Following lower limb strength training exercises, patients with stroke often experience muscle fatigue, which can frequently lead to falls. Therefore, this study aims to explore how lower limb muscle fatigue caused by squats affects the strength and balance of healthy individuals before extrapolating it to patients with stroke. Design: Cross-sectional study Methods: The study followed a cross-sectional design. The study was conducted on 30 healthy adults. Strength and balance were measured before and after performing wall squat exercises. Muscle strength was measured using a dynamometer, while balance was assessed with the S3 check system. A paired t-test was used for the analysis. Results: The knee extensor and hip extensor showed a significant decrease after wall squat (p < 0.05). However, there was no significant difference observed in knee flexor and hip abductor between before and after wall squat. Balance did not show a significant difference between before and after wall squat. Conclusion: Muscle fatigue caused by wall squats was found to reduce the strength of the knee and hip extensors, while having no impact on balance. The results of this study may serve as foundational data for future research targeting patients with stroke.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.4
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• pp.891-897
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• 2013

This study is purposed to propose indices in order to achieve goals such as preventing one-sided movement of balance, preventing injuries to joints of legs, improving muscular strength of legs, and maximizing sporting achievement. In terms of methodology, this study has compared foot pressure distribution during squat exercise. This study targets 10 male students in their 20s of Department of Physical Education and 10 male students in their 20s of other departments of P University located in B City. Skilled members have been selected out of those who have had regular weight training experiences for last 3 years. As a result of analysis on impact of squat exercise on foot pressure, conclusions have been obtained as shown below. As a result of analysis on foot pressure distribution of back feet of skilled members and unskilled members during squat exercise, it was found out that foot pressure of left foot of skilled members was 0.13kgf/s, and that of unskilled members was 0.28kgf/s, showing significant difference (p<.01). As a result of analysis on foot pressure ratio of back feet of skilled members and unskilled members during squat exercise, it was found out that foot pressure ratio of left foot of skilled members was 50.03%, and that of unskilled members was 67.18%, showing significant difference(p<.01).

• Journal of the Korean Society of Physical Medicine
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• v.15 no.4
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• pp.121-129
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• 2020

PURPOSE: This study aimed to propose an exercise technique that helps improve the skeletal muscle function while suppressing the symptoms of respiratory distress, by mediating squat exercises in whole-body vibration for patients with severe COPD, and comparing the post intervention pulmonary function and activity of quadriceps. METHODS: Totally, 21 patients with severe COPD were randomly assigned to two groups through clinical sampling: experimental group I included 11 patients (Squat exercise combined with whole-body vibration exercise), and experimental group II included 10 patients (Only squat exercise). Before intervention, we measured pulmonary function using a pulmonary function tester, muscle activity of quadriceps using surface EMG, and gait ability using the 6MWT. RESULTS: Comparison of intra-group changes in both experimental groups showed a significant increase in the activity of rectus femoris, vastus medialis, and vastus lateralis, and also in the 6MWT. Intra-group comparisons also revealed significant difference in the activity of rectus femoris, vastus medialis, and vastus lateralis (p < .05). CONCLUSION: Squat exercise combined with whole-body vibration significantly increased the activity of the quadriceps muscle, suggesting that this intervention helps maintain the function of skeletal muscles and prevent muscle atrophy. Therefore, studies to develop protocols using whole body vibration in clinical practice as an exercise method can safely be performed in severe COPD patients, as considered necessary.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.1
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• pp.33-40
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• 2014

The objective of this study was to assess leg muscle activities during whole body vibration (WBV) training with various squat position exercises. Subjects performed four different squat exercises on a vibration platform (VM-10, Sonicworld Co.) Ten healthy women volunteers (age $21{\pm}1.3years$, height $160{\pm}2.1cm$, weight $52{\pm}4.6kg$) were selected. EMG signals four leg muscles were taken and analyzed. The exercises were performed both with 10 seconds WBV and without 10 seconds WBV. Muscle activities during WBV were compared with non-vibration stimulus. In the result, EMG signals caused by WBV were significantly higher (P<0.05) compared with non-vibration stimulus in all leg muscles and squat exercises. The increase in muscle activity caused by Whole body vibration was significantly higher (P<0.05) in LS and OS compared with HU&HS.

• Physical Therapy Rehabilitation Science
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• v.12 no.1
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• pp.1-11
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• 2023

Objective: This study aimed to investigate the effects of squat posture, band position, and contraction type on the muscle activity of the hip abductors during resisted lateral band walking. Design: A cross-sectional survey study Methods: 24 healthy male subjects were recruited, and surface electromyography was used to measure the muscle activity of the gluteus maximus, gluteus medius, and tensor fascia lata of the dominant leg during lateral walking exercises. Resistance bands were applied to the knees, ankles, and feet in semi-squat and squat postures, and exercises were randomly performed under six different conditions. Results: The results showed significant differences in muscle activity in the gluteus maximus, gluteus medius, and tensor fascia lata according to posture, band position, and contraction type (p<0.05). The muscle activity of the hip abductors increased in the squat posture and with the band placed on the distal joint compared to the proximal joint (p<0.05). Additionally, muscle activity was higher in the eccentric contraction phase than in the concentric contraction phase (p<0.05). Contrary to previous studies, moving the resistance band from the ankle to the foot increased the muscle activity of the tensor fascia lata while the activity of the gluteus maximus and gluteus medius also increased. Conclusions: According to the results, squat posture with a resistance band placed on the feet and using an eccentric contraction phase were found to be the most effective methods for strengthening the hip abductors.